1. Technical Field
The disclosure relates to a radiation sensor, a cap, a combined ambient radiation and proximity sensor, a proximity sensor, an electronic communications device and a method of manufacturing a radiation sensor.
2. Description of the Related Art
Proximity sensors are used in many applications, including on mobile communications devices and vehicle parking sensors. Such proximity sensors typically comprise a radiation source and a corresponding detector, the detector comprising a relatively small number of exposed radiation sensitive pixels (e.g. a 10×10 array). Proximity sensing is achieved by: emitting, typically, light from the radiation source; capturing light which is reflected back to the detector by an object; and processing the reflected light to determine whether or not an object is covering the sensor.
Typically, mobile phone proximity sensors work simply by determining the intensity of radiation detected by the radiation sensor. When the intensity is above a threshold value, it is determined that an object is covering the sensor; conversely, when the intensity is below a threshold value, it is determined that no objects are covering the sensor.
Typical uses of a proximity sensor on a mobile phone include providing an indication to a processor that the screen can be switched off to save power when an external object is detected (e.g. when the user is making a call and part of the user's head is near the proximity sensor). Additionally or alternatively, the proximity sensor may provide an indication that some or all of the phone's input controls should be disabled when an external object is detected (e.g. to prevent a user from entering unintentional inputs during a call).